Adenoviral-mediated gene transfer in human and animal vein grafts using clinically relevant exposure times, pressures, and viral concentrations

This study examined the efficiency of adenoviral-mediated gene transfer in experimental vein grafts and cultured human saphenous vein under physiologic conditions using clinically relevant exposure times, pressures, and viral concentrations. The external jugular veins of 25 male New Zealand White rabbits were exposed to 0.5 mL of replication-deficient adenovirus vectors encoding β-galactosidase (AdlacZ), control adenovirus (AdBg/II), or vehicle at pressures ranging from 0 to 120 mmHg for 10 min. Veins were excised and grafted into the carotid circulation. After 5 days, the vessels were reexposed, excised, and stained with X-gal chromagen for β-galactosidase (β-gal) activity. Gene transfer was also performed in 13 segments of human saphenous vein discarded at the time of bypass grafting. The veins were cultured for 0-21 days and assayed for β-gal activity as above. Rabbit vein grafts exposed to high-pressure AdlacZ transfection showed significant transgene expression in 100% of grafts (39 ± 2% positive cells/hpf) while only 60% of those transfected at low pressure expressed β-gal (9 ± 3% positive cells/hpf). All human veins exposed to AdlacZ expressed β-gal to a variable degree (range 10-50% positive cells/hpf). No control grafts or veins expressed the transgene. Efficient adenoviral-mediated gene transfer in experimental vein grafts and human saphenous vein segments can be achieved using clinically feasible parameters of exposure time, pressure, and viral concentration.